1. Field of the Invention
The present invention relates to a sampling device or tool and a method for using said device in taking precise sample volumes in duplicate, triplicate and/or quadruplicate, of powder blends or emulsion mixtures at various depths simultaneously by utilizing dies with varying sample volumes. This device enables the procurement of these samples from very large blenders or containers by providing a segmented sampler design.
2. Description of the Prior Art
In the manufacture of solid dosage form pharmaceutical solids and semi-solid dosage forms, one of the critical processing steps is the blending of the active ingredient(s) with the inactive ingredient(s) in a blender or mixer. Before further processing of such mixtures, samples are taken from different areas of these mixtures and analyzed to check whether or not the active ingredient is uniformly distributed. Such a test is called a content uniformity test or a homogeneity test. Whenever a powder or a semi-solid mixture is tested for homogeneity, the test results would be influenced by the sample size and the sampling technique. In order to insure accurate testing, the sample size should be as close to the unit dose as possible; and the sampling technique should be such that the mixture is minimally disturbed during sampling. However, unit-dose sampling of mixtures with varying dosages and bulk densities requires multiple sampling devices. The other factors that compound this problem are the large range of mixer sizes, limited clearance between the top of the mixer and the ceiling, the large number of samples to be taken, the necessity for a duplicate, triplicate or quadruplicate set of samples, the requirement of thorough cleanability of the device, and the necessity of preventing leakage of semi-solid samples. All these factors together impose an economic penalty on the manufacturer.
The present invention overcomes these problems by providing a sampling device that permits the following advantages. (1) Unit-dose sampling is accomplished at various depths of the mixture by using dies of varying volumes. (2) The sampling location in the mixture is readily changed by the use of dummy or blank dies to block any of the sampling locations. (3) The option of taking duplicate, triplicate or quadruplicate samples from exactly the same area at each of the sampling locations is readily made by vertical and/or horizontal movement of only the internal sampling or receiving rod that accommodates two, three or four dies, respectively, at each of the sample cavities. (4) Large blenders/mixers are readily sampled by utilizing the sampling rod and the outer casing in sections that are joined above or within the blender/mixer. (5) Thorough cleaning of the outer casing is enabled by utilizing a removable solid cone tip.
A number of patents have been issued that address sampling of various materials. These patents will be discussed in the order of their perceived relevance to the claimed invention.
In Italian Patent No. 484,331 issued in November, 1954 to Dino Donadon, there is disclosed a sampler of immiscible liquids which consists of an inner tube containing partitioned volumes with apertures for each compartment, an outermost tube, and an intermediate tube with apertures which align with both the inner tube's apertures and corresponding apertures in the outermost tube. A portion of the second tube's apertures contains a filter. The innermost tube and the intermediate tube have separate handles for alignment of their respective apertures with the apertures of the outer tube in order to take samples of an immiscible liquid system. There is no disclosure of dies, facility for duplicate, triplicate or quadruplicate sampling, segmentation of the sampler, a separate cone tip, and the operation of his sampler without the essential intermediate tube and associated filters.
In U.S. Pat. No. 4,790,198 issued on Dec. 13, 1988 to Jon Awtry et al., a grain probe is disclosed having an inner tubular member's openings aligned with the outer tubular member's opening to take grain samples. The grain probe has a pointed end to aid in the penetration of the grain pile. There is no disclosure of individual dies, duplicate to quadruplicate sampling capability, segmentation of the grain probe or the removability of the pointed end.
In U.S. Pat. No. 3,080,760 issued on Mar. 12, 1963 to Henry D. Piersma, there is disclosed a disposable sample probe for bulk chemicals including powder. The probe is a simple two-tube device with alignment of separate cavities with the outer tube's apertures for taking samples. Again, there is no suggestion of the use of individual dies, duplicate to quadruplicate sampling and segmentation of the device.
In U.S. Pat. No. 2,875,615 issued on Mar. 3, 1959 to Orrion A. Ulvin, a grain and seed probe is disclosed which utilizes a spiral element within an apertured outer tube, but without any segmentation of the long probe.
In U.S. Pat. No. 4,744,256 issued on May 17, 1988 to Shale J. Niskin, there is disclosed a non-segmented water sampler device dropped from an airplane to obtain a single sample by utilizing a valving arrangement to open and close the sampler.
In U.S. Pat. No. 2,185,651 issued on Jan. 2, 1940 to John Sollie, there is disclosed a milk sampler including a rod (with a handle) to reduce sample volume capacity.
Finally, in U.S. Pat. No. 4,660,423 issued on Apr. 28, 1987 to John M. Armstrong et al., a water sampling apparatus is disclosed wherein sampling is initiated by in situ puncturing of a sealed tube to obtain one sample.
The prior art discussed in the parent patent is incorporated by reference herein.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.